Questions About W Bosons: Speed, Isolation & Existence

[Thinkor]

Has the speed of W (or Z) bosons ever been measured?
I presume not, because I have read they exist for only about 10^-25 seconds.

So, how is it known that they are not charged particles that move at the speed of light, with energy, but no mass, like photons?

Have they ever been isolated?

How is it known that they exist?

 

[mathman]

http://pdg.lbl.gov/

Look through the above. It contains lots of information about W and Z particles. Note that the W particles are charged.

 

[Bill_K]

The Z boson is uncharged, but we know its mass is about 90 GeV. Why? Because it takes a minimum of 90 GeV energy to make one!

 

[jtbell]

Have they ever been isolated?

How is it known that they exist?

Nobel Prize in Physics 1984

http://nobelprize.org/nobel_prizes/physics/laureates/1984/rubbia-lecture.pdf (PDF)